1. Field of the Invention
The present invention relates to a power unit layout structure for an automobile.
2. Description of the Related Art
As conventional power unit layout structures for automobiles, there is a known structure as described in Japanese Patent Application Laid-open No. H11-245668 in which an expandable body is expanded at the time of head-on collision of a vehicle, and a link body connecting an upper portion of a dash panel and a power therebetween is swung so that the power unit drops into a vacant space located below the power unit, and there is a known structure as described in Japanese Patent Application Laid-open No. H7-164895 in which a power unit is previously inclined and mounted below an inclining toe board which is located below a dash panel so that the power unit drops along the inclined toe board at the time of head-on collision of a vehicle.
In the case of the former conventional art, a vehicle height adjusting mechanism and its control means are necessary as the expandable body, which disadvantageously increases the costs. In the case of the latter conventional art, since the power unit is inclined, the power unit can not be applied to a vehicle unless the vehicle has design corresponding to this special layout, and the latter conventional art inferior in applicability.
Thereupon, the present invention realizes, with simple structure, a power unit layout structure for an automobile in which when a vehicle collides in a longitudinal direction thereof, a distance between a mounting chamber having the power unit and a partition wall partitioning a compartment is increased so that a crushing stroke can be increased and a collision energy can rationally be absorbed even if the expandable body is not expanded.
A first aspect of the present invention provides a power unit layout structure for an automobile for mounting a power unit in a mounting chamber partitioned by a partition wall on a front side or a rear side of a compartment, comprising:
a side member capable of buckling and deforming in a longitudinal direction with respect to a longitudinal collision of a vehicle;
a subframe located at a position lower than the side member and having an intermediate portion capable of folding and deforming by a longitudinal collision load;
a connecting member for connecting a lower portion of a power unit and the intermediate portion of the subframe; and
a rod for connecting an upper portion of the power unit and a longitudinal-direction end constituent material of the mounting chamber,
wherein when the vehicle collides in the longitudinal direction, the intermediate portion of the subframe is downwardly folded and deformed, and the power unit is rotated in the longitudinal direction around a lower connecting point by load transmission applied to an upper portion of the power unit through the rod.
According to the first aspect of the invention, if a collision load is input to the subframe by the longitudinal collision of the vehicle, the intermediate portion of the subframe is downwardly folded and deformed into a L-shape, the power unit is downwardly moved with respect to the vehicle body, the longitudinal-direction end constituent material is crushed, deformed and moved in the longitudinal direction, the collision load is input to the upper portion of the power unit through the rod, and the power unit is rotated in the longitudinal direction around the lower connecting point.
As a result, a distance of the shortest portion between the power unit and the partition wall is increased, the side member is appropriately buckled and deformed in the longitudinal direction, the collision energy can rationally absorbed and the partition wall can be suppressed from being deformed toward the compartment even if the entire length of the mounting chamber is not increased.